SchorschCould you be more specific. The sfc of most turbojets during that time period were between .9 and 1.1, which I have no details regarding the R-15 to say it was different. And you do realize the MiG-21 program had evolved to eventually field prototypes that used this same turbojet?
Then go and get it! 😀
The R-15 is optimized for high supersonic flight. What does that mean? Well, to be efficient at high Mach numbers a turbojet doesn’t need to have a really good compressor ratio at static conditions. Like the J-58 the engine starts to work more and more like a ramjet. The J-58 was specifically designed to be something like a morph between a ramjet and a turbojet. But the J-58 was really designed for Mach3, while the R-15 has to cover a wider range of speeds. It still is not optimized for subsonic flight. As such, it delivers poor thrust and miserable SFC at lower speeds.
Actually, that is a problem for some Russian engines of that time, which were too much optimized for supersonic flight. One should now that for supersonic flight things actually become easier for the turbo-jet.
SFC is nothing static, it is a function of Mach number, thrust setting and altitude. The values you quoted are either static sea level SFC (quite useless), or max continuous optimum altitude SFC (more useful, but often misleading).
In conclusion: fitting an engine optimized for a different flight regime into a different aircraft is stupid at best. Things aren’t that easy, you cannot surf through Wikipedia and compare dry thrust levels and diameter and by that find your favorite engine. OK, you can do that, but then please go to the children’s corner and play there. 😀
Regarding the MiG-21 prototypes: these were just that and in the text we can read very clearly that they never came past this stage. Of course, merging a more powerful engine with the right inlet/exhaust system to an airframe of Mach2+ performance will yield a M2.5+ fighter. If you really check the sources you’ll find that also F-4 and F-104 went far beyond their operational Mach numbers in tests. The engines theoretically produce more and more thrust at higher Mach numbers. The MiG-25 is not limited in excess thrust at its operational limit of M2.8 (M2.5 for normal peacetime operations), but it is limited by its engine overspeed limit. Beyond that limit the engine may become uncontrollable and ultimately fail.
Apart from that, the MiG-25 had problems with lateral control at those Mach numbers. It shows again: you either build a fighter or a Mach 2.5+ aircraft, both at the same time isn’t working.
SchorschBecause the military are stupid.
Stupid at drawing up initial requirements, stupid at changing those requirements at the end of the design and development phase, stupid at not future proofing the requirements.
And now imagine 10 of those on one table, needing to agree on one joined requirement. Sounds impossible, actually it often was. I still wonder how they figured out the Eurofighter and the Tornado and still came along with a reasonable aircraft. In the US the Navy and the Air Force are unable to agree on one aircraft.
I think they could have launched the A400M ten years earlier. It is the most urgend program in Europe.
Hope there is still a war when it enters service. :diablo:
SchorschDo you think the Leopard II was better?
It is not me but the majority of experts. Look how many nations have bought the machine. Anyways …
Whichever the case, the Gulf Wars demonstarted the big technological advantage of modern western armor. I don’t recall that we lost more than one tank in battle, if that. It was just amazing.
… the Iraqis used Soviet weapons mainly, but were a bad benchmark. With any other tank they had performed equally bad.
The capability of an isolated weapon system (tank or aircraft) does not really make a difference in a war. Even the US Army was able to win battles with the Sherman tank (actually, nearly all), which is considered an engineering disaster by most people.
SchorschThey wont roll it out again 😉 , i guess the tests should start on the ground in march or maybe a little earlier with first flight a month or so after that.
But they need to roll it out or will they take-off out of the hangar?
Boeing said “end of first quarter”, which I would guess is conservative. See how much I trust Boeing, I considered the later three of the total four earlier FF dates (Aug07, Aug/Sep07, Oct07, Nov/Dec07) as conservative. Guess the pilots just don’t like to fly in rainy weather.
SchorschWouldn’t it make sense to switch to a more passive system in surface2air defense? As we know, a stealth aircraft is hard to detect with conventional radar as the signal return is too low. Therefore it probably would make sense to divide radar emitter and radar receiver. With at least two emitters an receiver could identify target locations (theoretically). With emitters sending waves from multiple directions, the receiver is more likely to receive some signal.
Missiles would be guided by datalink with a possible terminal IR-guidance or active radar (quite useless against stealth aircraft).
The whole approach would be very demanding in terms of communication (the emitters need to send one by one, on the right frequency …).
SchorschNATO had built up enough with 4th generation fighters and Abrams tanks
I guess the Abrams tank wouldn’t make the big difference, especially as it was only second best on the battlefield. I can recommend a visit to the Fulda Gap museum to get a bit frightened about the whole issue. The nuclear landmines used there say it all.
Any conflict would largely be decided by the strategy. A surprise attack of one side against the other without warning would be devastating. However, it would become nuclear in a matter of days.
When you see the politics from mid 60s on, both sides were very eager to avoid any kind of confrontation.
SchorschI always wondered what something like a scaled up F1 with a Tumansky R-15 would of performed like on the market. Basically akin to the MiG-23PD prototype before the swingwing decision.
Oh, a disaster.
A turbo-jet with exceptionally bad specific fuel flow and pretty bad thrust-weight when not at supersonic.
Would be as useful as equipping a B747 with J-58.
SchorschI don’t remember any source claiming Iranians being able to produce 100% of Tomcat parts. The best figure I have ever seen was 80% of all necessary spares, usually it is even less.
A production of new Tomcats can be easily ruled out. Installing Russian engines or radars is very unlikely, IMHO.
And one set of 100% spares are not equal to one aircraft.
Installing new engines is a very delicate issues demanding engineering resources and lots of knowledge. Not something they do on the fly.
And I always ask: If they are so ###### advanced, why don’t they built a new aircraft? The F-14A (with now close to 30 years) is the worst point to start from.
As far as I know,the Phoenix was one of the systems they were able to reproduce.Not only that,but they also made an laser guided air to ground missile,based in part,off the Phoenix.
Why didn’t they produce a really useful missile instead of a copy of a 30 year old design, which would be 0% effective against current EW equipment?
This issue with buying a new aircraft is simple.No other aircraft is as flexable as the Tomcat,or has as good interception abilities,at least when you’re talking Russian or Chinese.
Wrong. Change their F-14A on a one-to-one basis against any currently produced fighter would bring advantage.
I must say, the Iranian F-14 is one of the most overrated aircraft in the world.
A good hint how you can hype your aircraft: just don’t tell about it. 😀
SchorschSomething real from 1972, when not all worked to text-book and the human factor controls such hardware in question. That crew did not discuss turn-rates and Gs by the way.
From the linked text:
“Get on the scope,” said Bud over the intercom, unaware that I didn’t have a scope boot. With L’il John’s radar out, I was the only hope for locking the enemy on the scope for a head-on launch of a Sparrow radar-guided missile. I hunched over the radar with my nose about a half inch from the screen to try to shield it from the glare. The bandit was low, but so were we. I leveled my antenna. At first I saw nothing but green snow. I reduced my gain control and made out a little blip above the ground clutter. I locked onto it, and an attack presentation popped up on the screen. The overtake looked good. It was him.
“Red Crown, Red Two’s got radar contact,” I announced. Dead ahead. Eleven miles. We were closing at 1,200 knots, in range for a Sparrow shot within seconds. “Red Crown, Red Two. Copy me?” Where was Crown? They had to clear us to fire. We were in optimum range, and the bandits weren’t turning this time.
“Red Crown, Red Crown. How do you read? Over!”
“Red Flight from Crown. Disregard! Disregard! Break it off! It’s friendly. I repeat. Bogey is friendly.” Seconds later two Air Force Wild Weasels zipped by to our port. I imagined the pilots giving us congenial little waves, blissfully unaware we’d nearly vaporized them.
That shows very nicely how difficult it was to track enemy aircraft even with a second crew member. I guess with that technology (and MiG-23M and MiG-25P hardly had anything better) a single pilot will barely able to use his BVR capability without very good guidance from the ground.
SchorschAerion is now taking money for SSBJ-s, too – though they still do not have any manufacturer…
Which is first class fraud.
They don’t have a manufacturer.
They don’t have engineering resources.
They don’t have capital.
SchorschYou think they will stabilise? (and actually come back down in price?)
Any particular reasons? 🙂
Yes. The oil prices already factored in many risks and issues, like growing demand, long term bottleneck in production and political risks (Iraq, Iran, Venezuela, …). The current surge is the result of speculation to some extent. Winter is nearing on the Northern hemisphere … the usual suspects. It will come back down again, but of course we will not have it at 30USD a barrel. I recently learned that German government based their growth prognosis on 80 USD/barrel, I guess that this is an agreed average for the coming year if no major crisis erupts.
SchorschA new experience, when compared to other cramped cockpits, like my “first love” F-104 or later ones, when I did enter a cockpit of a MiG-23 in Damgarten.
Some describe the cockpit view from a MiG-23 with something between tank and U-boat. :diablo:
Schorsch[From that year 1978+ we had a rising number of Floggers with the claimed capabilities long before, but not fullfilled through development delays! OKB did not hide that shortcomings really, but wishfull readers will not be bothered with such details!]
Means that MiG-23ML were actually entering frontline units when F-4E were withdrawn to secondary units and replaced by F-15A.
SchorschIt is true that probably the MiG-25 was by far the most difficult opponent for the F-4 in 1974, it was simply uncapable of intercepting it, the MiG-23 was more or less its equivalent and the Mirage F1 a very good design in 1975.
However the MiG-25 had a fear factor and military and technical merits to call it the bogie man of the F-4 pilots in 1974, so a combination of the MiG-25 and MiG-23 was too much for the F-4 in terms of air to air combat
Actually, the only real advantage of the MiG-25 was speed and altitude. The weapon system was outside the ground control network not really useful. The single pilot couldn’t cope with the workload. Any turning combat was of course not the MiG-25 discipline.
I think within the GCI network the MiG-25 is very useful, as it can use speed and altitude to attack unfriendly aircraft without giving them true abilities for counterattack.
One can see pretty well what the Soviets thought of their own aircraft: Even before it really became operational (~1973 for the -P) they planned the MiG-31 (first flight ~75), which had turbofan engines (the engines of the MiG-25 are as fuel efficient as an open fireplace), less (but still considerable) speed and better weapon system with a second crew member. Reason of course the new threat, no high and fast flying intruders any more.
The Soviet recycled the the MiG-25P into the MiG-25PD.
SchorschVery true – airlines have been forced to become much more efficient now. There was an article on the bbc the other day about the fuel price pressure forcing United to ground aircraft. Here is cnn on it.
More worryingly, there have been rumours that airlines have been cutting down on the reserve allocation (below legal limits) to save a bit.
The biggest problem I see is that the growing costs are actually not transferred to the customers. May sound strange, but it would be healthy for the industry if the costs for fuel are feeded to the customers directly. If so, demand will get lower, maybe we even will have a small decrease in overall traffic growth. But that would still be sutsainable by the industry, airlines and likewise manufacturers.
More devastating would be a battle between the airlines, that lose money in order to get market share. Very common occurance in the American market, less frequent in the rest of the world (I guess due to more restrictive market conditions in the rest of the world).
Boeing went out of the 90s with close to 90% market share and now stands somewhere at 50%. One reason was the downfall of the American airlines, which still did not recover completely.
An increase in prices and a small reduction in capacity in order to maintain a high load factor and low operational costs would be the best to bridge until in the near future oil prices stabilize a bit(they won’t get back to 30 bucks, but 70 USD is possible).
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